SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '581905ae3f31d432fd587c34fafc730c6bae472877b6eed2440ca99de71f6131' 
  AND token = 'ShtOq+S71navdVVwJoXzPZ4he9YB+3HDnWRFiBeOApc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}